bug#30547: Hurd patch for `patch` does not apply to latest release

[Manolis Ragkousis <manolis837@gmail.com>]

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Hello Leo,

On 02/20/18 14:20, Leo Famulari wrote:
> There is a new version of GNU Patch, 2.7.6:
> 
> https://ftp.gnu.org/gnu/patch/
> 
> I noticed that our patch, 'patch-hurd-path-max.patch', doesn't apply. I
> have an idea of how to adapt the patch, but I don't really have a way to
> test it.
> 
> Manolis, are you able to adapt the patch to Patch 2.7.6?
> 

I rebased the patch on the latest patch master. The only thing I am not
sure is why the old patch was changing PATH_MAX with tost->st_size + 1.
I can't remember for the life of me. Also I can't remember why this
patch isn't part of patch upstream yet.

The old diff

-      char *buffer = xmalloc (PATH_MAX);
+      char *buffer = xmalloc (tost->st_size + 1);

while now I made it:
-      char *buffer = xmalloc (PATH_MAX + 1);
+      char *buffer = xmalloc (tost->st_size + 2);

Anyhow it should work now, can you try it?

Thank you!
Manolis

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diff --git a/src/util.c b/src/util.c
index 1cc08ba..eee8514 100644
--- a/src/util.c
+++ b/src/util.c
@@ -460,12 +460,12 @@ move_file (char const *from, bool *from_needs_removal,
 
 	  /* FROM contains the contents of the symlink we have patched; need
 	     to convert that back into a symlink. */
-	  char *buffer = xmalloc (PATH_MAX);
+         char *buffer = xmalloc (fromst->st_size + 1);
 	  int fd, size = 0, i;
 
 	  if ((fd = safe_open (from, O_RDONLY | O_BINARY, 0)) < 0)
 	    pfatal ("Can't reopen file %s", quotearg (from));
-	  while ((i = read (fd, buffer + size, PATH_MAX - size)) > 0)
+	  while ((i = read (fd, buffer + size, fromst->st_size - size)) > 0)
 	    size += i;
 	  if (i != 0 || close (fd) != 0)
 	    read_fatal ();
@@ -610,10 +610,10 @@ copy_file (char const *from, char const *to, struct stat *tost,
 
   if (S_ISLNK (mode))
     {
-      char *buffer = xmalloc (PATH_MAX + 1);
+      char *buffer = xmalloc (tost->st_size + 2);
       ssize_t r;
 
-      if ((r = safe_readlink (from, buffer, PATH_MAX)) < 0)
+      if ((r = safe_readlink (from, buffer, tost->st_size)) < 0)
 	pfatal ("Can't read %s %s", "symbolic link", from);
       buffer[r] = '\0';
       if (safe_symlink (buffer, to) != 0)